1.[12-6y+( )]-[-5y^2-( )+( )]=2y^2+3y-4

问题描述:

1.[12-6y+( )]-[-5y^2-( )+( )]=2y^2+3y-4
2.已知x^2-xy=8,xy-y^2=3.则x^2-y=( ),x^2-y^2=( )
a^3+a-4-( )=a^3-a^2+a

我直接填上了啊!
(1)[12-6y+(-3y^2)]-[-5y^2-(9y)+(16)]=2y^2+3y-4
(2)x^2-y^2=11
总的说,第1题答案是-3y^2 9y 16
第2题是11